docs: def tb2radiance(self, tb_, **kwargs):
          """Get the radiance from the brightness temperature (Tb) given the
          band name.
  
          Input:
            tb_: Brightness temperature of the band (self.band)
  
          Optional arguments:
            lut: If not none, this is a Look Up Table with tb and radiance values
              which will be used for the conversion. Default is None.
  
            normalized: If True, the derived radiance values are the spectral radiances for the band.
              If False the radiance is the band integrated radiance. Default is True.
  
          """
          lut = kwargs.get('lut', None)
          normalized = kwargs.get('normalized', True)
  
          if self.wavespace == WAVE_NUMBER:
              if normalized:
                  unit = 'W/m^2 sr^-1 (m^-1)^-1'
              else:
                  unit = 'W/m^2 sr^-1'
              scale = 1.0
          else:
              if normalized:
                  unit = 'W/m^2 sr^-1 m^-1'
              else:
                  unit = 'W/m^2 sr^-1'
              scale = 1.0
  
          if lut:
              ntb = (tb_ * self.tb_scale).astype('int16')
              start = int(lut['tb'][0] * self.tb_scale)
              retv = {}
              bounds = 0, lut['radiance'].shape[0] - 1
              index = np.clip(ntb - start, bounds[0], bounds[1])
              retv['radiance'] = lut['radiance'][index]
              if retv['radiance'].ravel().shape[0] == 1:
                  retv['radiance'] = retv['radiance'][0]
              retv['unit'] = unit
              retv['scale'] = scale
              return retv
  
          planck = self.blackbody_function(self.wavelength_or_wavenumber, tb_) * self.response
          if normalized:
              radiance = integrate.trapz(planck, self.wavelength_or_wavenumber) / self.rsr_integral
          else:
              radiance = integrate.trapz(planck, self.wavelength_or_wavenumber)
  
          return {'radiance': radiance,
                  'unit': unit,
                  'scale': scale}